Question

4 carry out the calculation indicated and round off the answer to the correct number of significant figures.
a 13 + 4.547 =
b 1.874 x 8.60 =
c 15.657 x 12.9 =
d 1800 / 2.133 =
e 2.31+3.2 =
f 14.212 - 13.15 =

Explanation:

Step1: Calculate 13 + 4.547

$13+4.547 = 17.547$. Rounding to the correct number of significant figures (since 13 has 2 significant figures), the answer is 18.

Step2: Calculate 1.874×8.60

$1.874\times8.60=16.1164$. Rounding to 3 significant figures (8.60 has 3 significant figures), the answer is 16.1.

Step3: Calculate 15.657×12.9

$15.657\times12.9 = 202.9753$. Rounding to 3 significant figures (12.9 has 3 significant figures), the answer is 203.

Step4: Calculate 1800÷2.133

$1800\div2.133\approx843.882$. Rounding to 3 significant figures (1800 is considered to have 2 or 3 significant figures, and for division we go by the least number of significant figures among non - exact numbers, here 2.133 has 4, but we assume 1800 has 3 for better precision), the answer is 844.

Step5: Calculate 2.31 + 3.2

$2.31+3.2 = 5.51$. Rounding to 2 significant figures (3.2 has 2 significant figures), the answer is 5.5.

Step6: Calculate 14.212−13.15

$14.212 - 13.15=1.062$. Rounding to 3 significant figures (13.15 has 4 significant figures, but 14.212 and 13.15 are being subtracted, and we go by the decimal - place rule for addition/subtraction, and then significant figures), the answer is 1.06.

Answer:

a. 18
b. 16.1
c. 203
d. 844
e. 5.5
f. 1.06